The present invention relates to a centrifugal precipitator for precipitating oil mist from the crankcase ventilation gas of an internal combustion engine, the centrifugal precipitator having a housing, a drivable rotor mounted rotatably therein, and a rotational drive for the rotor, the housing having a crude gas inlet for crankcase ventilation gas that is to be deoiled, a pure gas outlet for deoiled crankcase ventilation gas, and an oil outlet for oil precipitated from the crankcase ventilation gas, the housing having a multipart construction with a main element that surrounds the rotor and that holds the bearing thereof, having a housing cover containing the rotational drive, and having a housing floor built onto the main element from below, through which at least the oil outlet runs, and the housing being capable of being mounted by a flange onto a counterflange of the associated internal combustion engine or of a module forming part of the associated internal combustion engine.
A centrifugal precipitator of the type indicated above is known from WO 2010/951 994 A1. Here it is essential that the centrifugal precipitator has an electric motor as a rotor drive and has means for cooling the electric motor, at least one cooling element preferably being provided as a means for cooling the electric motor. Preferably, the housing has a lower part having an inlet for crude gas that is to be supplied for the rotor, and having an outlet for oil precipitated from the crude gas, the lower part being capable of being produced as a separate individual part, and being capable of being connected to the rest of the housing in various rotational positions relative thereto, preferably by welding or by being plugged together. The centrifugal precipitator can be equipped with a connecting flange with which it can be flange-mounted onto a module base, in particular of an oil filter module, or onto a cylinder head cover of the internal combustion engine, some or all of the required flow connections from and to the internal combustion engine running through the connecting flange.
In this known centrifugal precipitator, it is regarded as disadvantageous that it has a relatively heavy weight, because in order to achieve the necessary mechanical stability its housing is made up to the largest possible extent of metal, in particular aluminum. Due to the complex routing of the crude gas, pure gas, and precipitated oil inside the precipitator, it is necessary for the housing to have a multipart construction. Such a housing made of a plurality of metal parts is relatively expensive to manufacture, in particular if various connection interfaces, such as connecting pieces and flanges, are present in and on the housing, which have to be processed separately by machining, which is expensive.